The present invention relates to a plumbing device and more particularly to a plumbing device including a radially outwardly resiliently expansible plug or sleeve which can be expanded into sealing engagement with the inner surface of a pipe in which it is disposed.
Several pipe-plugging devices have heretofore been proposed but many such known devices have relied on the frictional sealing engagement between an expansible sleeve and the inner surface of a pipe to prevent displacement of such a device from a pipe within which it is disposed. One such device is described in Austrian Pat. No. 98,176 while another is described in U.S. Pat. No. 2,322,842.
Although such known pipe-plugging devices are very useful where it is desired to prevent the flow of liquid from the end of a pipe, they are obviously limited in their use to conditions under which the fluid pressure to which they are subject is insufficient to cause axial slipping of the expanded plug in the pipe.
It has also heretofore been suggested to provide a pipe-plugging device which incorporates an external pipe clamp to reduce the risk of slipping of the expanded plug under fluid pressure. One such device is described in U.S. Pat. specification No. 3,326,243. The device described in that particular specification does not, however, permit access to the end of the pipe while the plug is secured therein.
Frequently, it is desired temporarily to plug a pipe against the flow of fluid while a plumbing element, such as a valve, is secured to the end of the pipe or while a faulty plumbing element, such as a leaking valve, is removed from the pipe end and replaced by a new one.
It is a principal object of this invention to provide a plumbing tool or device including a radially outwardly resiliently expansible sealing plug or sleeve which can be expanded within a pipe into sealing engagement with the inner surface of the pipe and which device provides coupling of the expanded sleeve to an external pipe-clamping shackle so as to prevent slippage of the sleeve within the pipe under the action of fluid pressure, while still permitting working access to the end of the pipe.
Another object of this invention is to provide a plumbing device for the aforesaid purpose and which device has a relatively simple construction and is very easy to use.
A further object of the invention is to provide a plumbing device of the aforementioned type and which is capable of being used on a pipe carrying a fluid at a relatively high pressure without danger of slipping of the pipe-sealing plug.
Another object of this invention is to provide a method and device whereby the sealing plug of a device of the aforesaid type can be introduced into a pipe against fluid pressure therein.
One further object of this invention in accordance with a preferred feature thereof is to provide a device of the aforementioned type and by means of which an expansible sealing plug can be inserted into a pipe against fluid pressure therein with reduced stress on the pipe and its mountings.
Other objects of the invention will become apparent as the description herein proceeds.